Timber‐glass composite: concepts for glued bracing floor elements

The objective of several research projects was to investigate alternative constructions of stiffening glass fronts, which replace St. Andrew's cross wind bracings and costly frameworks. These are only suitable for vertical use and for absorbing the horizontally acting forces in the directions of the panes. A follow‐up research project was started with the aim of developing calculation and design concepts for glued bracing floor and roof elements. Taking into consideration short‐term behaviour and seismic performance the practical applications considered is to develop bracing composite elements. These transparent and light‐weight elements could substitute the conventional bracing elements and/or heavy massif constructions. The research project “Timber‐glass composite: concepts for glued bracing floor and roof elements” is going to develop highly transparent and load‐bearing composite floor structures. These shall stiffen the building at floor and roof level and should be able to withstand loads in combined pane‐ and panel loading. In the research project composite timber and glass sections for load bearing and stabilizing purposes will be developed. The special feature of such a further development of existing timber‐glass composite elements is the presence of an interrupted formation of adhesive joints. The compressive stresses occurring in the glued joints will be reduced by the punctiform blocking of the glass panes. From this, a transmission of shear stresses can be achieved, which is currently only possible to a very limited extent but is absolutely necessary for use. The glass has not a stiffening bearing function, merely functions as an outer cover in the same time. For the development of new composite elements made of timber, glass and adhesives the identification of relevant material properties and setting up of requirement specifications for adhesive bonding of glass to timber is substantial and are addressed in the research project together with issues like moisture and temperature fluctuations. In order to counteract summer overheating and protect privacy, the glass elements should be equipped with switchable panes. Thus, light architecture that is integrated into the environment should still be easy to realize.